Sterile field clot capture module for use in thrombectomy system

ABSTRACT

A clot capture module can include a housing, a chamber inside the housing, a window, and a filter. The window permits visual inspection of a clot inside the chamber. The clot can access the chamber via an incoming flow path configured to direct blood from an aspiration catheter to an upstream surface of the filter. An aspiration control valve can block the flow of incoming aspirated blood until actuated to permit inflow of aspirated blood. An outgoing flow path can direct blood from a downstream surface of the filter to a remote vacuum canister.

INCORPORATION BY REFERENCE

This application claims the priority benefit under 35 U.S.C. § 119(e) ofU.S. Provisional Patent Application No. 63/341,926, filed May 13, 2022,and is a continuation-in-part of U.S. patent application Ser. No.17/357,490, filed Jun. 24, 2021, which claims the priority benefit under35 U.S.C. § 119(e) of U.S. Provisional Patent Application No.63/044,511, filed Jun. 26, 2020, and which is a continuation-in-part ofU.S. patent application Ser. No. 17/125,723, filed Dec. 17, 2020, andissued as U.S. Pat. No. 11,065,018 on Jul. 20, 2021, which claims thepriority benefit under 35 U.S.C. § 119(e) of U.S. Provisional PatentApplication No. 62/950,058, filed Dec. 18, 2019, and U.S. ProvisionalPatent Application No. 63/064,273, filed Aug. 11, 2020, the entiretiesof each of which are hereby incorporated by reference herein.

BACKGROUND

Removal of blood clots from the vascular system (thrombectomy) using atrans vascular approach may be accomplished at any of a variety oftreatment sites, such as arteries in the extremities, veins for deepvein thrombosis (DVT), large veins and arteries (central vessels) suchas iliac veins and arteries, the aorta, the inferior vena cava andpulmonary arteries to treat pulmonary emboli (PE).

For example, venous thromboembolic disease (VTE) is a worldwide crisis.There are over 10 million cases of DVT and PE diagnosed globally peryear, with 1 million cases occurring in the United States and over700,000 in France, Italy, Germany, Spain, Sweden, and the United Kingdomcombined each year. There are approximately 60,000 to 100,000 deathsfrom PE in the United States each year. DVT and PE are part of the samecontinuum of disease, with over 95% of emboli originating in the lowerextremities. When PE occurs, the severity depends on the embolic burdenand its effect on the right ventricle as well as underlyingcardiopulmonary comorbidities. Death can result from the acute increasein pulmonary artery (PA) pressure with increased right ventricular (RV)afterload and dysfunction.

Patients with high-risk PE have been treated primarily with thrombolytictherapy delivered systemically or more locally through Catheter DirectedThrombolytics. These approaches result in multiple catheterization labvisits, lengthy hospital stays and often lead to bleeding complications.Newer approaches to PE treatment include single session thrombectomytreatments without the use of thrombolytics. These thrombectomytreatments include delivering a catheter into the PA to remove thethrombus through aspiration, and secondary tools may also macerate ordisrupt the thrombus prior to aspiration. While thrombectomy results infewer bleeding complications and reduced hospital stays compared tothrombolytics, there is much to be improved upon given the challenges ofthe procedure itself, including the ability to capture a broad spectrumof thrombus types and reduce the total volume of blood loss during theprocedure.

The thrombectomy catheter is introduced through an introducer puncturein a large diameter vein. A flexible guide wire is passed through theintroducer into the vein and the introducer is removed. The flexibleguidewire provides a rail for a flexible guide catheter to be advancedthrough the right atrium into the right ventricle and into the pulmonaryartery. The flexible guidewire is removed and replaced with a stiffguidewire. The large diameter thrombectomy catheter with support dilatoris then advanced over the stiff guidewire to the pulmonary artery andthe dilator is removed. If the large diameter thrombectomy catheter isnot successful in accessing or aspirating thrombus in a more distalportion of the vessel, a smaller diameter catheter may be insertedthrough the large diameter catheter.

In addition, peripheral arterial occlusive (PAO) disease occurs in morethan 4% of individuals over age 40 and markedly increases in incidenceafter the age of 70. Acute PAO is usually due to thrombosis of theperipheral vasculature and is associated with a significant risk of limbloss. In order to preserve the limb, therapy for acute PAO centers onthe rapid restoration of arterial patency and blood flow such as throughmechanical thrombectomy in procedures similar to those described above.

Clot aspiration using certain commercial vacuum-assisted thrombectomysystems may sometimes need to be terminated due to the risk of excessiveblood loss by the patient, especially when using large aspirationcatheters. During aspiration thrombectomy, when the catheter tip fallsout of contact with the thrombus or other occlusive material, the tip isexposed to healthy blood and full flow of blood through the catheterensues. Under such conditions, the total volume of blood loss may beexcessive, and in some cases, may result in premature termination of theprocedure. For example, during a procedure when the catheter entershealthy blood and full aspiration flow ensues, the blood loss rate canbe on the order of 30-40 cc per second with an 24 French size catheter.With a maximum tolerable blood loss on the order of about 500 mL, thecatheter cannot run in unrestricted mode for more than approximately 10to 15 seconds. The aggregate blood loss may reach an unacceptable levelbefore sufficient clot is removed.

Thus, notwithstanding prior efforts, there remains a need for animproved technology for removing or reducing thrombotic restrictions andocclusions within either the patient's arterial or venous blood vessels.

SUMMARY

There is provided in accordance with one aspect of the presentinvention, a clot capture module for use in a thrombectomy system, suchas within the sterile field. The clot capture module comprises ahousing; a clot capture chamber in the housing; a window in the housingto permit visual inspection of the clot chamber; and a filter in theclot chamber, visible through the window, the filter having an upstreamsurface and a downstream surface.

An incoming flow path is configured to direct incoming blood from anaspiration catheter against the upstream surface of the filter. Anaspiration control valve is provided in the incoming flow path,configured to block or permit the flow of incoming blood. An outgoingflow path is configured to direct blood from the second side of thefilter to a remote vacuum canister.

The clot capture module may further comprise a vent valve, openable topermit an optically transparent media such as air or saline to be drawninto the clot chamber, enabling blood to be evacuated from the clotchamber to a remote canister. The upstream surface of the filter may bevisible through the window, so that clot accumulated on the upstreamsurface can be visually observed through the window, once the vent hasbeen opened to evacuate blood from the clot capture chamber. The windowmay comprise a transparent cylindrical portion of the housing.

The upstream surface of the filter may be substantially planar.Alternatively, the upstream surface of the filter may be convex. Thefilter may comprise a tubular porous membrane such as a cylinder, andthe upstream surface of the filter may be on a radially outwardly facingsurface of the membrane. The tubular filter membrane may enclose afiltered blood chamber which is in communication with the outgoing flowpath.

The module may further comprise an aspiration control, for controllingthe aspiration control valve. The aspiration control may comprise arocker switch, configured to selectively collapse or allow reopening ofa collapsible tubing. The aspiration control valve may be normallyclosed, and may be spring biased into the closed configuration.

The clot capture module may be provided in combination with a vacuumline leading to an aspiration pump and canister, wherein the clotcapture module is configured to reside within a sterile field and theaspiration pump and canister are outside of the sterile field. Thevacuum line may be at least about 30 inches or 50 inches or more inlength. In some instances, a manually actuated aspiration device (e.g.,a syringe) may be used in addition to, or as an alternative to, anaspiration pump to permit a user to manually apply aspiration throughthe vacuum line.

There is provided in accordance with another aspect of the presentinvention, a thrombus engagement tool, configured to advance through anaspiration catheter and engage thrombus. The thrombus engagement toolcomprises a rotatable core wire having a proximal end and a distal end;and a thrombus engagement tip on the distal end of the core wire. Thetip may comprise a helical thread; an advance segment on a distal sideof the thread and a trailing segment on a proximal side of the thread.The advance segment, helical thread and trailing segment may all bemolded onto the core wire.

The thrombus engagement tool may further comprise a projection on thecore wire, underneath at least one of the advance segment and thetrailing segment, to form an interference fit with the thrombusengagement tip. The projection may comprise an annular ring, which maybe a radiopaque marker. The thrombus engagement tool may comprise afirst radiopaque marker under the advance segment and a secondradiopaque marker under the trailing segment.

An outer periphery of the helical thread may substantially conform to aninside surface of a cylinder. The thread may comprise a proximal surfacewhich inclines radially outwardly in a proximal direction to define aproximally opening undercut.

The thrombus engagement tool may further comprise a handle on theproximal end of the core wire configured for hand turning the core wire.A limit bearing surface may be provided on the handle, for limitingdistal projection of the thrombus engagement tip relative to a distalend of the aspiration catheter.

There is further provided a method of removing embolic material from avessel with mechanical and aspiration assistance. The method comprisesthe steps of providing an aspiration catheter having a central lumen anda distal end; advancing the distal end to obstructive material in avessel; applying vacuum to the lumen to draw clot at least partiallyinto the lumen; and introducing a thrombus engagement tool into thelumen. The thrombus engagement tool may have a tip with an axial lengthof no more than about 1 cm or about 5 mm and a helical thread having amajor diameter that is at least about 0.015 inches smaller than aninside diameter of the lumen, to provide an aspiration flow path throughthe lumen around the outside of the tip. The method further comprisesmanually rotating the tip to engage clot between the tip and an insidewall of the lumen.

A method of aspirating a vascular occlusion from a remote site,comprises the steps of advancing an elongate tubular body through avascular access site and up to a vascular occlusion, the tubular bodycomprising a proximal end, a distal end, a central lumen, and a stopsurface. A rotatable core is advanced distally through the lumen until alimit surface carried by the core rotatably slidably engages the stopsurface to provide a rotatable bearing which limits further distaladvance of the core within the lumen. Vacuum is applied to the lumen andthe core is manually rotated to engage thrombus. The advancing therotatable core may be accomplished after the step of advancing theelongate tubular body through the vascular access site and up to thevascular occlusion. The core may be a solid core wire or a cannulatedstructure such as a hypotube or microcatheter having a central lumenextending axially between a proximal opening and a distal opening.

The core may carry a proximal handle, and the limit surface may becarried by the handle. The tubular body may include a proximal hub, andthe stop surface may be carried by the hub. The core may carry anengagement tip having a helical thread, and the engaging thrombus stepmay comprise pinning thrombus between a first side of the tip and aninside surface of the tubular body.

There is also provided an inserter for guiding a device through ahemostasis valve, comprising an elongate tubular body, having a proximalend, a distal end and a central lumen; a laterally facing concavelanding zone on the proximal end, having a radius of curvature thatincreases in the proximal direction; and an axially extending slit inthe sidewall, extending from the distal end to the landing zone. Thetubular body may further comprise a tapered distal tip, and a proximalpull tab to facilitate removal of the inserter from the device. Asurface of the landing zone may comprises a different color than anoutside surface of the tubular body, to facilitate visualization of thelanding zone and advancing the distal end of the device into the tubularbody.

A method of passing a device through a hemostasis valve may comprise thesteps of providing an inserter, having a tubular body with a splitsidewall; advancing the tubular body through a hemostasis valve;advancing a device through the tubular body and beyond the hemostasisvalve; and proximally retracting the tubular body so that the deviceescapes laterally from the tubular body through the split sidewall,leaving the device in place across the hemostasis valve.

The advancing the tubular body step may comprise advancing a tapereddistal tip on the tubular body through the hemostasis valve. Theadvancing the tubular body through the hemostasis valve step may beaccomplished with the device pre loaded inside the tubular body.

A distal nose segment of the tubular body may expand in diameter inresponse to advancing the device therethrough. The device may be athrombus engagement tool or a secondary catheter. The secondary cathetermay be an aspiration catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a thrombus removal system in accordancewith the present invention.

FIG. 2 is a perspective view of a flow control module.

FIG. 3 is an elevational of cross-sectional view through the flowcontrol module of FIG. 2 .

FIG. 4 is a schematic view of the dual vacuum chamber configuration thatproduces an accelerated aspiration response.

FIG. 5 is a qualitative fluid flow rate diagram at the catheter tipfollowing opening of the vacuum control valve.

FIG. 6A is a side elevational view of a thrombus engagement tool.

FIG. 6B is an enlarged detail view of the distal end of the thrombusengagement tool of FIG. 6A.

FIG. 6C is a longitudinal elevational cross-section through the thrombusengagement tool of FIG. 6B.

FIGS. 7A-7E are side elevational views of various embodiments ofthrombectomy catheters.

FIG. 8 is a cross-sectional view through a distal portion of theembolectomy catheter showing a side wall construction.

FIG. 9 is a cross-sectional view through a distal portion of theembolectomy catheter showing the radiopaque marker and inclined distalface.

FIGS. 10A-10B are perspective views of an inserter tool to facilitatepassing a catheter through a hemostasis valve.

FIG. 10C is an end view of the inserter of FIGS. 10A and 10B.

DETAILED DESCRIPTION

Referring to FIG. 1 , there is illustrated a thrombectomy system such asfor PE or DVT aspiration procedures. The system 10 includes athrombectomy catheter 12, having an elongate tubular body 14 extendingbetween the proximal end 16 and a distal end 18. A central lumen 20 (notillustrated in FIG. 1 ) extends between a proximal catheter connector 22and a distal port 24 on the distal end 18.

Although primarily described in the context of an aspiration catheterwith a single central lumen, catheters of the present invention canreadily be modified to incorporate additional structures, such aspermanent or removable column strength enhancing mandrels, two or morelumen such as to permit drug, contrast or irrigant infusion or to supplyinflation media to an inflatable balloon carried by the catheter, or anycombinations of these features, as will be readily apparent to one ofskill in the art in view of the disclosure herein. In addition, thedisclosure will be described primarily in the context of removingobstructive material from the vasculature, but it will be understood tohave applicability as an access catheter for delivery and removal of anyof a variety of diagnostics or therapeutic devices with or withoutaspiration.

The catheters disclosed herein may readily be adapted for use throughoutthe body wherever it may be desirable to distally advance a low profilehigh flexibility catheter into a variety of type of vasculature, such assmall or large vasculature and/or tortuous or relatively straightvasculature. For example, catheter shafts in accordance with anyembodiment described herein may be dimensioned for use throughout theneurovascular, coronary and peripheral vasculature, the gastrointestinaltract, the urethra, ureters, Fallopian tubes and other lumens andpotential lumens, as well. The catheter shaft construction of anyembodiment herein may also be used to provide minimally invasivepercutaneous tissue access, such as for diagnostic or therapeutic accessto a solid tissue target (e.g., breast or liver or brain biopsy ortissue excision), delivery of laparoscopic tools or access to bones suchas the spine for delivery of screws, bone cement or other tools orimplants.

Catheter 12 will have a length and diameter suitable for the intendedaccess point and target location. In one example, referring to FIG. 1 ,the catheter 12 may have an effective length from the distal end ofmanifold or hub 22 to distal tip 18 generally no more than about 230 cm,no more than about 210 cm, no more than about 180 cm, or no more thanabout 160 cm. and typically from about 50 cm to about 150 cm, from about90 cm to about 130 cm, or from about 105 cm to about 115 cm. The outerdiameter of the catheter 10 may be from about 0.035 inches to about 0.15inches, from about 0.09 inches to about 0.13 inches, and may be lower ina distal segment than in a proximal segment.

The inner diameter of the catheter 12 in a single central lumenembodiment may be greater than or equal to about 0.1 inches, greaterthan or equal to about 0.088 inches, or greater than or equal to about0.08 inches, or greater than or equal to about 0.06. The inner diameterof the catheter 12 in a single central lumen embodiment may be less thanabout 0.20 inches or 0.15 inches, or less than or equal to about 0.11inches, less than or equal to about 0.1 inches, less than or equal toabout 0.088 inches, or less than or equal to about 0.07 inches, andoften no more than about 0.095 inches.

In the illustrated embodiment, the catheter 12 is releasably connectableto a flow control module 28 by way of a complementary connector module30. Connector module 30 provides a releasable connection tocomplementary catheter connector 22 and may include a side port 32 forreleasable connection to tubing 34 which may lead to a valve 36.Connector module 30 may additionally comprise a hemostasis valveconfigured to receive another device such as a guidewire or thrombusengagement tool, discussed below.

Valve 36 may selectively place tubing 34 into communication with sideport 37 or the flow control module 28 discussed in greater detail below.Side port 37 may be placed into communication with a source of mediasuch as saline, contrast solution or medication, or a manifold 38 whichcan provide selective communication with each. The use of valve 36allows infusion of a desired media without detaching the tubing 34 fromthe connector module 30.

Referring to FIGS. 2 and 3 , the flow control module 28 is incommunication with the valve 36 by way of a distal tube 44. Flow controlmodule 28 is in communication with the selector valve 49 by way of aproximal tube 46. This establishes a flow path between the distal port24 through the catheter 12 through the various tubing and flow controlmodule 28 to the pump assembly 42. In an alternate implementation of theinvention, the flow control module 28 may be integrally formed withinthe hub of thrombectomy catheter 12 to which the catheter 12 may beremovably or non-removably attached or within the connector module 30.In some instances, a manually actuated aspiration device (e.g., asyringe) may be used in addition to, or as an alternative to, anaspiration pump assembly 42 to permit a user to manually applyaspiration through the vacuum line. It will be understood by one havingskill in the art that a manually actuated aspiration device may be in inaddition to, or as an alternative to, the pump assembly described in anyembodiment herein.

Flow control module 28 may include a flow regulator such as an on-offcontrol for regulating flow through the flow path between the catheter12 and pump 42. The flow regulator is configured to provide a reversiblerestriction in the flow path, such as by an expandable or contractibleiris, a ball valve or other rotary core valve, leaf valve, a pinchtubing, or others known in the art.

In one implementation, the flow regulator comprises a collapsibleportion 29 of the tubular wall defining the flow path, such as a sectionof polymeric tubing. An actuator 31 positioned adjacent the tubing ismovable in response to a control such as a push button or toggle switch48 between a first position where it compresses the tubing, therebycompletely restricting flow, and a second position where it has movedaway from the tubing, allowing the tubing to resume its full insidediameter and allow fluid flow. The actuator 31 may be spring biased orhave another default driver in the direction of the first (restricted)position, and only movable into the second (open) position in thepresence of an affirmative mechanical force or release of a constraintallowing the flow path to open. Upon removal of the momentary “on”command, the actuator 31 automatically resumes the first position,obstructing flow.

The actuator 31 may be driven by a mechanical control such as a lever orrotatable knob, or an electrically driven system such as a solenoid,operated by any of a variety of buttons, levers, triggers, foot pedalsor other switches known in the art, depending upon the desiredfunctionality.

The flow control module 28 may contain a filter chamber 33 for example,which is in communication with the vacuum canister 58 on the pumpassembly 42 by way of elongate aspiration tubing 40. The toggle switch48 is in between the filter chamber 33 and the catheter 12. In a defaultoff position of some embodiments, this allows the entire length of theaspiration tubing 40 and the filter chamber 33 to reach the same lowpressure as the aspiration canister 58 on the pump 42.

Additional details of the filter assembly and related structures areillustrated in FIG. 3 . A filter assembly 35 includes an outer tubularsidewall 37 having a transparent window 39. In some implementations theentire tubular sidewall 37 can be a transparent window. The side wall 37encloses a filter 41. The filter 41 includes a filter sidewall 43defining an interior (downstream) chamber (not illustrated) for filteredblood.

Upon opening the flow path by activating the switch 48, blood andthrombus are drawn in the direction from catheter 12 via vacuum line 44through a first filter aperture 45 and into the clot collection chamber33. Any thrombus will be captured on the outside (upstream side) offilter 43. Blood is drawn through the filter 43 and proximal tubing 46en route to the canister 58. In the illustrated example, the filter 43is tubular however it may alternatively be planar or other shapedepending upon the desired configuration.

The switch 48 may thereafter be closed to compress tubing 29 and isolatethe catheter 12 from the vacuum source. A normally closed vent 47 may bemomentarily opened, to permit intake of an optically transparent mediasuch as saline or ambient air. This allows residual blood in the chamber33 to be drawn through the filter 43 and aspirated out via proximaltubing 46, enabling visualization of any clot on the surface of thefilter 43 through the window 39. The vent 47 may be manually actuated bya user and/or automatically actuated by the system. In some instances, auser may manually actuate the vent 47 through actuation of a button 62located on the flow control module 28.

For example, the vent 67 may be normally closed, and then transitionedto an open configuration when the button 62 is being actuated (or viceversa). When in the open configuration, the vent 67 may expose the clotcollection chamber 33 to an ambient environment. In some instances,exposure of the chamber 33 to the ambient environment allowing intake ofair and acceleration of blood flow through the clot collection chamber33 and towards the proximal tubing. Increased acceleration of blood flowdue to vent 47 actuation may facilitate visualization of the clot bydisplacing the amount of blood or other fluids from the optical pathbetween the window and the filter and/or decrease the amount of timerequired for the physician to accurately identify the clot in thechamber 33. The valved vent also allows the physician to deliverpulsatile negative pressure waves at the distal opening 24.

In the illustrated embodiment, the flow control module 28 comprises aproximal housing 31 and a distal housing 29 separated by the transparenttubular sidewall 35. The tubular sidewall 35 and the filter 43 arecarried by the proximal housing 31. Housing 29 and tubular sidewall 35may be joined at a releasable connection 33 that, in some instances,includes a gasket 59 to form a sealed connection. Complementary surfacestructures (e.g., inclined corresponding grooves and pins or flanges)may permit rapid attachment and detachment. For example, the proximalhousing 31 and the distal housing 29 may be rotated relative to eachother (e.g., by relative rotation across the gasket) to disconnect thehousings from each other.

The filter 43 may be attached to any one of the distal housing 29 or theproximal housing 31 upon disconnection of the housings. The tubularsidewall 35 may be attached to either one of the distal housing 29and/or the proximal housing 31 such that, upon disconnection, thetubular sidewall 35 may remain attached to one of the housings 29, 31.Upon detaching and separating the proximal housing 31 from the distalhousing 29, the tubular sidewall 35 may be configured to remain aroundthe filter 43 or may be configured to be removed from over the filter43. In either instance, disconnection of the housings 29, 31 from eachother can expose the filter 43 and allow a clot to be easily accessedand removed.

The interior surface of the clot collection container 33 may comprise acoating to provide one or more of a variety of properties to the clotcollection containers 33. In some instances, the coating may beconfigured to enhance visualization through at least a portion of theclot collection container 33 (such as the transparent window 39). Thecoating may be configured to inhibit blood accumulation or increaseblood repellant properties. In some instances, the clot collectioncontainer 33 may comprise a coating to inhibit foam formation during anaspiration procedure. The coatings may be located at least partiallyalong an interior surface of the tubular sidewall 35 and/or the clotcollection container 33 or along an entire interior surface of thetubular sidewall 35 and/or the clot collection container 33. In someinstance, the coating is located along an interior surface of thetransparent window 39. The coating can be both hydrophobic andoleophobic. In some instances, the coating may have some hydrophilicfeatures on a portion of the polymer to increase oleophobic properties.

Aspiration pump assembly 42 may be releasably placed into communicationwith flow control module 28 such as by a luer connection betweenselector valve 45 and tubing 40. Aspiration pump assembly 42 may includea vacuum pump 50, and may also include a vacuum gauge 51, and anoptional pressure adjustment control 54. The vacuum gauge 51 is in fluidcommunication with the vacuum pump and indicates the vacuum pressuregenerated by the pump. The pressure adjustment control 54 allows theuser to set to a specific vacuum pressure. Power button 56 activates thepump 50.

The vacuum canister 58 may be provided with a vent 53 to atmosphere,opened or closed by a valve. In one implementation the valve is normallyclosed to permit vacuum in the canister to reach a desired low pressure.The valve may be momentarily opened as desired to permit introduction ofair and reduction of the vacuum, such as to reduce foaming within thevacuum canister 58.

The vent may function to reduce foaming and increase visibility withinthe canister. In some instances, the vent 53 comprises a permanentlyopened vent such as in a lid or side wall of the vacuum canister. Thevent may comprise an aperture formed through the lid or side wall havinga diameter of no more than about 0.5 mm or 0.25 mm and may be a lasercut hole through a metal sheet which may be in the form of a disccarried by the lid.

In addition to or as an alternative to the vent, the inside surface ofthe canister 58 may be provided with a coating of one or more materialsto inhibit foaming of blood under vacuum. The coatings may be located atleast partially along or entirely along an interior surface of thevacuum canister 58. The coating can be both hydrophobic and oleophobic.In some instances, the coating may have some hydrophilic features on aportion of the polymer to increase oleophobic properties.

Any of a variety of controls may be utilized to operate the various pumpfunctions, including switches, buttons, levers, rotatable knobs, andothers which will be apparent to those of skill in the art in view ofthe disclosure herein. Aspiration pump 50 may alternatively be amanually activated pump such as a syringe.

In some applications, it may be desirable to provide a non occlusiverestriction of flow between the vacuum canister 58 and the flow controlmodule 28. A flow restrictor may be coupled such as by luer connectorsin series with the vacuum line 40. In one implementation the flowrestrictors enables toggling between a low flow and a high flowconfiguration. The flow restrictors may comprise a variable restrictorthat may be adjusted by a user. This may be accomplished by selectivelydiverting flow between a relatively smaller diameter and larger diameteraperture, a variable diameter aperture, or other flow regulators such asany of those disclosed in the United States patent publication No.2021/0315597 to Buck, et al, entitled Aspiration System with AcceleratedResponse, the disclosure of which is hereby incorporated in its entiretyherein.

In one particular implementation, a rotatable drum is provided with afirst transverse flow path having a first diameter. The drum isrotatable within a housing having an inlet port and an outlet port. Thedrum may be rotated to place the inlet port into fluid communicationwith the outlet port through the first flow path. A second flow pathhaving a second, different diameter also extends transversely throughthe drum, rotationally offset from the first flow path. The drum may berotated to place the inlet port into communication with the outlet portthrough the second flow path, thereby providing a flow rate through thedrum different from the flow rate provided by the first flow path.

The filter chamber 33 on the flow control module 28 or on the connectormodule 30 is spaced apart from the remote vacuum pump 42 and vacuumcanister 58 to provide enhanced aspiration performance. Conventionalaspiration pumps and filters are intended to be placed outside of thesterile field and may be far enough away from the patient to require alength of aspiration tubing 40 between the pump assembly 42 and thecatheter 12 to be at least about 50 inches or about 100 inches or more.For example, the tubing 40 may be about 102 inches.

The pump typically includes an aspiration canister 58 for bloodcollection. When aspiration is desired in a prior art system, a valve isopened to place the low pressure canister 58 in communication with thecatheter 12 by way of the aspiration tubing 40, to aspirate materialfrom the patient. But the length of the aspiration tubing extending frominside to outside of the sterile field operates as a flow restrictor,causing a delay between the time of activating the vacuum button on thepump assembly 42 and actual application of suction to the clot at thedistal end of the catheter.

In the illustrated implementation, the only flow restriction between asource of vacuum (filter chamber 33) and the patient is the relativelyshort aspiration pathway between the on/off valve in the handpieceactuated by toggle switch 48 and the distal end 18 of the catheter. Whenthe aspiration control 48 is activated to open the flow path, the flowrestriction and enclosed volume on the patient side of the filterchamber 33 is low relative to the flow restriction and enclosed volumethrough aspiration tubing 40 on the pump side of the filter chamber 33.

This dual chamber configuration produces a rapid spike in negativepressure experienced at the distal end 18 of the catheter 12 uponactivation of the aspiration control 48, and rapid filling of thechamber 33. The response time between activating the aspiration control48 and realizing suction actually experienced at the clot issignificantly faster and allows significantly higher initial flow thanthe response time realized in a conventional system having only a vacuumchamber 58 located at the pump assembly 42 outside of the sterile field.

The spike of negative pressure experienced at the distal end of thecatheter will fade as pressure equilibrium is reached between the filterchamber 33 and canister 58. When the aspiration control 48 is closed,the vacuum pump 50 will gradually bring the pressure in the filterchamber 33 back down to the level in the vacuum canister 58 at the pump.

A simplified fluid flow diagram is illustrated in FIG. 4 , and aqualitative flow rate diagram is illustrated in FIG. 5 . The flowrestriction between chamber 33 and the distal end 18 of catheter 12 issmall relative to the flow restriction between the vacuum canister 58and the vacuum chamber 33. This allows a negative pressure peakexperienced at distal end 18 almost instantaneously upon activation ofvacuum switch 48. The flow rate of material into the catheter 12 rapidlyreaches a peak and subsides as vacuum chamber 33 fills with aspiratedmaterial. The vacuum in chamber 33 declines to a minimum, and slowlyrecharges by the large vacuum chamber 58 and associated pump throughtubing 40 when the toggle switch 48 is moved into the closed position.In some instances of use, a clinician may choose to close the vacuumswitch 48 at or shortly following the maximum flow rate, just giving ashort burst or series of bursts of pulsatile vacuum to facilitatespiration of thrombus into the catheter 12. In use, a similar effect maybe established by utilizing the vent 47. The vacuum in chamber 33 maydecline to a minimum as the button 62 is actuated such that the vent isopened. Thereafter, the vacuum chamber 33 may slowly recharge by thelarge vacuum chamber 58 and associated pump through tubing 40 when thebutton 62 and vent 47 are moved into the closed position. In someinstances of use, a clinician may choose to open the vent 47 at orshortly following the maximum flow rate, just giving a short burst orseries of bursts of pulsatile vacuum to facilitate spiration of thrombusinto the catheter 12.

If the application of vacuum is not able to aspirate the clot into thecatheter, an elongate flexible thrombus engagement tool may be advancedthrough the aspiration catheter, to facilitate retrieval of the clot.The thrombus engagement tool may comprise an elongate flexible shafthaving a proximal hand piece such as a knob configured to be rotated byhand. The distal end carries a clot engagement tip which may include oneor more radially outwardly extending engagement structures such as ahelical thread.

Referring to FIGS. 6A-6C, a thrombus engagement tool 80 may comprise anelongate flexible shaft 82 having a proximal end 84 and a distal end 86.A proximal hand piece such as a torquing handle 88 may be configured tobe rotated by hand. Distal end 86 carries a clot engagement tip 90 whichmay include one or more radially outwardly extending structures such asa helical thread 92. The handle 88 may have an indicium of rotationaldirection such as a printed or molded arrow 94 which indicates thedirection to rotate the handle 88 in order for the helical thread 92 toengage clot.

Referring to FIG. 6B, the distal tip 90 includes a helical thread 92extending between a distal thread end 96 and a proximal thread end 94and supported by flexible shaft 98. The axial length of the distal tip90 is at least about 5 mm or 10 mm or 15 mm or 20 mm and in someembodiments no more than about 30 mm or 20 mm measured along theflexible shaft 98. Preferably, the axial length will be within the rangeof from about 20 mm to about 25 mm.

The helical thread 92 wraps around the axis at least about 1 or 2 or 4or more full revolutions, but in some embodiments no more than about 10or no more than about 6 revolutions. Preferably, the thread 92 wrapsaround the axis within the range of from about 2.5 to about 4.5revolutions. In some embodiments the axial length along the threadedportion of the tip is within the range of from about 5 to about 15 mm,and preferably within the range of from about 8 mm to about 12 mm.

The helical thread 92 on this implementation may have a constant pitchthroughout its length. The pitch may be within the range of from about 5to about 10 threads per inch depending upon desired performance. Forexample, the thread to thread spacing in the axial direction may bewithin the range of from about 2 mm to about 6 mm, preferably from about3 mm to about 4 mm.

Alternatively, the thread may have multiple pitches (e.g. stepped orgraduated) designed to engage, transport or grasp thrombus within thecatheter lumen. A distal pitch may be less than a proximal pitch. Thepitch may vary continuously along the length of the thread, or may stepfrom a first, constant pitch in a proximal zone to a second, differentpitch in a distal zone of the thread. The thread 92 may comprise acontinuous single helical flange or may have a plurality ofdiscontinuities to produce a plurality of teeth or serrations, arrangedhelically around the core wire.

The maximum OD of the thread 92 is preferably smaller than the diameterof a sliding fit within the intended catheter lumen, and may generallybe at least about 0.015 inches or at least about 0.010 inches smallerthan the catheter lumen ID. In some implementations, the max OD of thetip may be significantly less than the inside diameter of the catheterlumen to allow more space for the thrombus along the side of the tip butstill create significant grasping force via lateral engagement of thehelical threads with the thrombus.

In one implementation, the maximum helical thread diameter is about0.110 inches, and the catheter lumen ID is about 0.275 inches (24F) (a0.165 inch gap between the helical threads and catheter wall). Inanother implementation, the maximum OD of the tip is within the range offrom about 0.03 to about 0.06 inches within a catheter having a distalend ID within the range from about 0.068 inches to about 0.073 inches.This leaves a substantial tip bypass flow path.

In certain applications, the max OD of the tip is no more than about 35%or no more than about 40% or no more than about 60% of the ID of thecorresponding catheter and may be within the range of from about 35% toabout 55% of the catheter ID. In some instances, the max OD of the tipmay slightly less than the ID of the corresponding catheter to provide asliding fit within the intended catheter lumen. For example, the max ODof the tip may be no less than about 90% or no less than about 95% or noless than about 97% of the ID of the corresponding catheter.

Since this implementation of the thrombus engagement tool does not haveany centering structures for the tip 90 or shaft 82, the tip 90 willnormally be pushed to one side of the aspiration lumen. When a clotbecomes lodged between the tip 90 and the opposing inside surface of theside wall of the catheter, manual manipulation such as rotation of thetip 90 can engage the clot like a worm gear and either grasp the clot(e.g., by pinning it against the opposing catheter sidewall) forretraction or facilitate freeing the blockage and aid in ingestion ofthe clot into the catheter. Manual manipulation may also include axialproximal and distal reciprocation along with rotation, duringaspiration, which can facilitate ingestion of the clot into thecatheter.

Thus, an unimpeded flow path is created in the annular (if the tip werecentered) space between the maximum OD of the tip, and the ID of thecatheter lumen. This annular flow path cooperates with the vacuum andhelical tip to grab and pull obstructive material into the catheterunder rotation and vacuum. The annular flow path is significantlygreater than any flow path created by manufacturing tolerances in a tipconfigured to shear embolic material between the tip and the catheterwall.

Additional aspiration volume is obtained as a result of the helicalchannel defined between each two adjacent threads of the tip. A crosssectional area of the helical flow path of a tip having a maximum OD inthe range of from about 0.0400 to about 0.0406 inches will generally beat least about 0.0003 square inches, and in some embodiments at leastabout 0.00035 or at least about 0.000375 inches. The total aspirationflow path across the helical tip is therefore the sum of the helicalflow path through the tip and the annular flow path defined between theOD of the tip and the ID of the catheter lumen.

Aspiration occurs both through the helical channel formed betweenadjacent helical threads as well as around the outside of the tip suchthat the assembly is configured for engaging and capturing embolicmaterial but not shearing it between a sharp edge of the thread and theinside wall of the catheter.

The distal advance segment 100 advantageously permits the thrombusengagement device 80 to at least partially move past the thrombuswithout “pushing” the thrombus in a distal direction as the tip 90 isadvanced. This may inhibit the thrombus (or any particulate thereof)from passing downstream within the vessel during engagement of thedevice 80 with the thrombus.

In some instances, the distal advance segment 100 can comprise acontinuation of the helical thread 92. For example, the distal advancesegment 100 may comprise a threaded segment continuing from the helicalthread 92. The threaded distal advance segment 100, in some instances,may maintain an outer diameter consistent with the remainder of thehelical thread 92. The threaded distal advance segment 100, in someinstances, may comprise a thread that tapers in a distal directiontowards a smaller outer diameter relative to the remainder of thehelical thread 92. For example, the helical thread 92 may comprise aproximal cylindrical segment and a distal tapered segment that extendsalong the distal advance segment 100.

The profile of the tip 90 in an end view along the axis of rotation maybe circular and/or, in some instances, may vary to create a non circularpattern around the axis of rotation. For example, profile may comprise ahelical pattern, such as an oval cross-section that rotates along theaxis of rotation to create the helical profile. The tip as seen in anend elevational view thus may exhibit a major diameter and a minordiameter. The minor diameter may be no more than about 95% or 90% or 80%or 70% of the major diameter, depending upon desired performance. In theillustrated example, the outer edge 93 of the thread 92 lies along thesurface of a cylinder.

In the illustrated implementation, an outer edge 93 of the thread 92thus has a linear surface in the axial direction, substantiallyconforming to the surface of a cylinder. A distal side 95 of the thread92 is inclined radially outwardly in a proximal direction. A proximalside 97 of the thread 92 also inclines radially outwardly in a proximaldirection thereby defining a proximally facing undercut along the lengthof the thread.

Referring to FIGS. 6B and 6C, the illustrated tip 90 includes anatraumatic, tapered distal advance segment 100 extending between anatraumatic distal tip at 102 and a transition to the distal end 96 ofthe thread 92. Helical thread 92 extends proximally from the transitionto a proximal end 94 of the helical thread 92. In some instances, atrailing segment 104 may extend between the proximal end 94 of thethread and the proximal end 106 of the tip.

The axial length of the distal advance segment 100 may be at least about5 mm or at least about 8 mm or 9 mm and generally less than about 15 mm,and in some implementations is within the range of from about 8 mm toabout 12 mm.

The outside diameter of the flexible shaft 82 is generally less thanabout 0.02 inches, or less than about 0.015 inches and, in oneimplementation, is about 0.008 inches. In some instances, the flexibleshaft 82 may comprise a distal tapered section. The distal taperedsection may advantageously increase tip flexibility and/or maximizeaspiration. The outside diameter at the distal end of the distal taperedsection of the flexible shaft 82 is generally less than about 0.01inches, or less than about 0.008 inches and, in one implementation, isno more than about 0.006 inches.

The outside diameter of the advance segment 100 at distal tip 102 isgenerally less than about 0.024 inches, or less than about 0.020 inchesand, in one implementation, is about 0.018 inches. The maximum outsidediameter of the advance segment 100 and helical thread 92 may be withinthe range from about 0.020 to about 0.045 inches, and, in oneimplementation, is less than about 0.040 inches, such as about 0.035inches. The advance segment, helical thread and trailing segment of thetip 90 may be molded as a single piece over the flexible shaft 82 usingany of a variety of polymers known in the catheter arts.

Referring to FIG. 6C, a first radiopaque marker 110 may be carried onthe flexible shaft 82 beneath the advance segment 100. A secondradiopaque marker 112 may be carried on the flexible shaft 82 within thetrailing segment 104. Each radiopaque marker may comprise a radiopaquetube or a coil of radiopaque wire such as a platinum iridium alloy wirehaving a diameter about 0.002 inches and positioned or wrapped aroundthe flexible shaft 82 and soldered to the flexible shaft 82 to producean RO sleeve or coil having an outside diameter of less than about 0.020inches, such as about 0.012 inches. The radiopaque markers may alsoprovide an axial interference fit between the flexible shaft 82 and theadvance segment 100 and trailing segment 104 to resist core wire axialpull out from the tip 90 (tip detachment).

In certain implementations, the maximum OD of the thread 92 exceeds themaximum OD of the advance segment 100 by at least about 15% or 25% or30% or more of the OD of the advance segment 100, to facilitate crossingthe clot with the advance segment 100 and engaging the clot with thethread 92.

Depending upon the clinical application, it may be desirable to controlthe extent to which, if any, the distal tip 102 can extend beyond thedistal end of the catheter 12. In certain implementations, the distaltip 102 may be permitted to extend at least about 2 cm or 3 cm andpreferably as much as 4 to 8 cm beyond the catheter (such as to permitmanual removal of engaged thrombus), but generally will be limited toextend no more than a preset distance such as 12 cm or 8 cm or 5 cmbeyond the catheter (e.g., within the range of from about 5 cm to about10 cm) depending upon desired performance.

Distal advance of the tip 102 may be limited by providing mechanicalinterference at the desired distal limit of travel. In oneimplementation, a distal stop surface 114 which may be on the handle 88(see FIG. 6A) provides an interference engagement with a complementaryproximal surface (e.g. proximal surface 33 on connector module 30 or onthe catheter hub) carried by the aspiration catheter through which thethrombus engagement tool 80 is advanced. Alternatively, a distalengagement surface can be carried anywhere along the length of thethrombus engagement tool 80, for sliding rotational engagement with acomplementary proximally facing stop surface carried by the catheter.Additional details of distal limit configurations may be found in U.S.patent application Ser. No. 17/036,258 filed Sep. 29, 2020 and entitledEmbolic Retrieval Catheter, which is hereby expressly incorporated inits entirety herein by reference.

The limit on distal advance of the helical tip may enable a firstconfiguration in which the distal tip may be advanced through thecatheter and placed at a first position approximately aligned with thedistal end of the catheter 12. The physician may then advance the tip toa second position extending beyond the distal end of the catheter suchas for inspection and cleaning purposes.

A position indicator 85 may be carried by the flexible shaft 82 spacedapart from the distal surface 114 by a distance corresponding to themaximum length of the thrombus engagement tool intended to extend beyondthe distal end of the catheter. When the position indicator 85 islocated at a corresponding reference point relative to the catheter hub,the distal tip 102 may be positioned approximately at the distal end ofthe catheter. This way the physician will know that any further distaladvance of the thrombus engagement tool will be extending beyond thedistal end of the catheter. The maximum extension will be reached whenthe distal surface 114 contacts the catheter hub.

The position indicator 85 may comprise any of a variety of visual ortactile features, such as a color change or a colored band surroundingthe flexible shaft 82. In a visual indicium implementation (color changeor circumferential line) the distal tip 102 may be positionedapproximately at the distal end of the catheter when the indicator isvisible just outside of the hub. In another implementation, the positionindicator 85 comprises the transition between the distal end of the hypotube 87 and the underlying flexible shaft 82. This provides hapticfeedback as the indicator (step in outside diameter) encounters andpasses through the valve of the RHV. The hypo tube 87 additionallyfunctions as a strain relief or anti buckling feature and may have anaxial length within the range of from about 3 cm to about 15 cm and insome implementations within the range of from about 5 cm to about 9 cm.

Referring to FIG. 7A, there is illustrated one example of an outerjacket segment stacking pattern for a progressive flexibility catheterof the type discussed in connection with FIG. 1 . A distal segment 120may have a length within the range of about 1-3 cm and a durometer ofless than about 35 D or 30 D. An adjacent proximal segment 122 may havea length within the range of about 4-6 cm, and a durometer of less thanabout 35 D or 30 D. An adjacent proximal segment 124 may have a lengthwithin the range of about 4-6 cm, and a durometer of about 35 D or less.An adjacent proximal segment 126 may have a length within the range ofabout 1— 3 cm, and a durometer within the range of from about 35 D toabout 45 D (e.g., 40 D). An adjacent proximal segment 128 may have alength within the range of about 1-3 cm, and a durometer within therange of from about 50 D to about 60 D (e.g., about 55 D). An adjacentproximal segment 130 may have a length within the range of about 1-3 cm,and a durometer within the range of from about 35 D to about 50 D toabout 60 D (e.g., about 55 D). An adjacent proximal segment 132 may havea length within the range of about 1-3 cm, and a durometer of at leastabout 60 D and typically less than about 75 D. More proximal segmentsmay have a durometer of at least about 65 D or 70 D.

The distal most two or three segments may comprise a material such asTecothane and/or PEBAX, and more proximal segments may comprise PEBAX orother catheter jacket materials known in the art. At least three or fiveor seven or nine or more discrete segments may be utilized, having achange in durometer between highest and lowest along the length of thecatheter shaft of at least about 10 D, preferably at least about 20 Dand in some implementations at least about 30 D or 40 D or more.

FIGS. 7A-7E illustrate various embodiments of catheters, at least someof which incorporate a plurality of catheter outer jacket segments withvarying lengths and/or hardness for varying flexibility along the lengthof the catheter body. It will be understood that any of the featuresshown or described in connection with any of the catheters of FIGS.7A-7E can be used with any of the embodiments described and/orcontemplated herein. It will also be understood that any of the featuresdescribed and/or contemplated in connection with any of the embodimentsdisclosed herein can be utilized with any of the catheters described inconnection with FIGS. 7A-7E. As with all embodiments in thisspecification, any feature, structure, material, method, or step that isdescribed and/or illustrated in the embodiments of FIGS. 7A-7E can beused with or instead of any feature, structure, material, method, orstep that is described and/or illustrated in any other embodiment ofthis specification.

FIGS. 7B-7E illustrates embodiments of various catheters 400, 500, 600.The catheters 400, 500, 600 may include differing properties (e.g., suchas length, diameter, etc.) such that one or more of the catheters 400,500, 600 may interact with any of the other catheters 400, 500, 600 inany various manner. In one instance, as illustrated by FIG. 7E, each ofcatheters 400, 500, 600 may comprise a different size to permit thecatheters 400, 500, 600 to at least partially extend through one or moreof the other catheters 400, 500, 600. The lengths of each of thecatheters 400, 500, 600 may vary so as to permit a smaller catheter topass through and extend distally beyond a larger catheter in atelescoping manner.

For instance, catheter 500 may be configured to pass through and extendbeyond catheter 400. By way of further example, catheter 600 may beconfigured to pass through and extend beyond at least one of catheter500 or catheter 400 in a telescoping manner. While FIG. 7E illustratesan example telescoping catheter stack including each of catheters 400,500, 600, it will be understood by one having skill in the art that anycombination of catheters 400, 500, 600 may be utilized. For example, asystem may incorporate the use of catheter 400 and catheter 500, the useof catheter 400 and catheter 600, or the use of catheter 500 andcatheter 600.

Catheter 400 may comprise an 8F catheter. In some instances, catheter400 comprises a diameter larger than the diameter of any of theremaining catheters in a system. Additionally, or alternatively,catheter 400 may comprise an overall length shorter than the length ofany of the remaining catheters in a system. In this manner, catheter 400may comprise the outermost catheter in a telescoping system and maypermit any of the remaining catheters 500, 600 to extend distally beyonda distal end of catheter 400. The catheter 400 may comprise a lengthbetween about 35 cm and about 105 cm or, a length between about 45 cmand about 95 cm. The catheter 400 may comprise a length of from about 50cm to about 90 cm. The catheter 400 may comprise a length at leastshorter than any catheter with a diameter smaller than catheter 400(e.g., such as catheter 500, 600).

Catheter 500 may comprise a 6F catheter. In some instances, catheter 500comprises a diameter in between the diameters of the remaining cathetersin a system. Additionally, or alternatively, catheter 500 may comprise alength in between the lengths of the remaining catheters in the system.In this manner, catheter 500 may comprise a middle catheter in atelescoping system and may be configured to pass through and extendbeyond one or more catheters while also permitting another catheter toextend distally beyond a distal end of catheter 500. The catheter 500may comprise a length between about 120 cm and about 155 cm or betweenabout 130 cm and about 145 cm. The catheter 500 may comprise a length ofabout from 135 cm to about 137 cm. The catheter 500 may comprise alength at least longer than any catheter with a diameter larger thancatheter 500 (e.g., such as catheter 400). The catheter 500 may comprisea length at least shorter than any catheter with a diameter smaller thancatheter 500 (e.g., such as catheter 600).

Catheter 600 may comprise a 5F catheter. In some instances, catheter 600comprises a diameter smaller than the diameters of the remainingcatheters in a system. Additionally, or alternatively, catheter 600 maycomprise a length longer than the lengths of any of the remainingcatheters in the system. In this manner, catheter 600 may comprise aninnermost catheter in a telescoping system and may be configured to passthrough and extend beyond one or more of the other catheters. Thecatheter 600 may comprise a length between about 145 cm and about 175 cmor between about 155 cm and about 165 cm. The catheter 600 may comprisea length of about 160 cm. The catheter 600 may comprise a length atleast longer than any catheter with a diameter larger than catheter 600(e.g., such as catheter 400, 500).

One or more of the catheters 400, 500, 600 may include a coil and/or abraid in the sidewall extending through at least a portion of thesidewall of the catheter 400, 500, 600, as discussed herein. The braidmay have properties that vary along the length of each catheter 400,500, 600 to generate a variety of desired characteristics of thecatheter 400, 500, 600. For example, a wire density of the braid mayvary gradually or in steps along the length of the catheter 400, 500,600 and/or vary between discrete sections of the catheter 400, 500, 600.

Catheter 600 may comprise one or more discrete sections with braidproperties varying between one or more of the sections. In someinstances, catheter 600 may comprise a first section, a second (e.g.,intermediate) section, and a third distal section. However, it will beunderstood by one having skill in the art that the catheter 600 maycomprise a fewer number of sections (e.g., one section or two sections)or a greater number of sections (e.g., four sections or greater). Asidewall property, such as a length and/or a wire density the braidalong a respective section, may vary between the sections. In someinstances, a pics per inch (ppi) count of the braid in connection withthe wire density of the braid may gradually transition between one ormore of the catheter sections. For example, the ppi count of the braid,in some instances, may remain generally consistent through a length ofthe first section and a length of the third section but graduallytransition along the length of the second, intermediate section.

The first section of catheter 600 may have a length of at least about 20cm. For example, the length of the first section may be from about 25 cmto about 35 cm or, in one example, about 30 cm. The braid through thefirst section may have a wire density of at least about 100 ppi. Forexample, the braid through the first section may have wire density of atleast about 120 ppi or, more specifically, about 130 ppi.

The third section of catheter 600 may have a length of at least about100 cm. For example, the length of the third section may be from about120 cm to about 140 cm or, more specifically, about 130 cm. The braidthrough the third section may have a wire density of no greater thanabout 85 ppi. For example, the braid through the third section may havewire density from about 70 ppi to about 80 ppi.

The second section of catheter 600 may be an intermediate sectionbetween the first section and the third section. The second section mayhave a length of at least about 3 cm. In some instances, the secondsection may have a length no greater than about 20 cm or, morespecifically, no greater than about 10 cm. For example, the length ofthe second section may be about 5 cm. The braid through the secondsection may have a wire density of no greater than the wire density ofthe first section and no less than the wire density of the thirdsection.

Catheter 500 may comprise one or more discrete sections with braidproperties varying between one or more of the sections. In someinstances, catheter 500 may comprise a first section, a second (e.g.,intermediate) section, and a third section. However, it will beunderstood by one having skill in the art that the catheter may comprisea fewer number of sections (e.g., one section or two sections) or agreater number of sections (e.g., four sections or greater). A sidewallproperty, such as a length and/or a wire density the braid along arespective section, may vary between the sections. In some instances, appi count of the braid in connection with the wire density of the braidmay gradually transition between one or more of the catheter sections.For example, the ppi count of the braid, in some instances, may remaingenerally consistent through a length of the first section and a lengthof the third section but gradually transition along the length of thesecond, intermediate section.

The first section of catheter 500 may have a length of at least about 20cm. For example, the length of the first section may be from about 25 cmto about 35 cm or, in one example, about 30 cm. The braid through thefirst section may have a wire density of at least about 100 ppi. Forexample, the braid through the first section may have wire density of atleast about 120 ppi or, in one example, about 130 ppi.

The third section of catheter 500 may have a length of at least about 80cm. For example, the length of the third section may be from about 100cm to about 120 cm or, in one example, about 105 cm. The braid throughthe third section may have a wire density of no greater than about 100ppi. For example, the braid through the third section may have wiredensity from about 80 ppi to about 90 ppi.

The second section of catheter 600 may be an intermediate sectionbetween the first section and the third section. The second section mayhave a length of at least about 3 cm. In some instances, the secondsection may have a length no greater than about 20 cm or, morespecifically, no greater than about 10 cm. For example, the length ofthe second section may be about 5 cm. The braid through the secondsection may have a wire density of no greater than the wire density ofthe first section and no less than the wire density of the thirdsection.

Catheter 400 may comprise one or more discrete sections with braidproperties varying between one or more of the sections. In someinstances, catheter 400 may comprise one section. However, it will beunderstood by one having skill in the art that the catheter 400 maycomprise a greater number of sections (e.g., two sections, threesections, four sections, or greater). For example, catheter 400 maycomprise three sections as described in connection with either one orcatheter 500 or catheter 600. A sidewall property, such as a lengthand/or a wire density the braid, may vary along catheter 400. In someinstances, a ppi count of the braid in connection with the wire densityof the braid may gradually transition to increasing flexibility in adistal direction along catheter 400. The section of catheter 400 mayhave a length of at least about 40 cm. For example, the length of thesection may be from about 50 cm to about 60 cm or, in one example, about55 cm. The braid through the section may have a wire density of at leastabout 80 ppi. For example, the braid through the section may have wiredensity of at least about 90 ppi.

The braid, in some instances, may extend along an entire length of thecatheter sidewall. In some instance, a junction between the braid and acoil is not present in the catheter and/or the catheter sidewall doesnot incorporate a coil. It will be understood that this braidconfiguration may be applied to any catheter disclosed herein,including, but not limited to, catheters 400, 500, 600.

One or more of the catheters 400, 500, 600 may an outer jacket segmentstacking pattern for a progressive flexibility catheter. The outerjacket segment may each have properties that vary along the length ofeach catheter 400, 500, 600 to generate a variety of desiredcharacteristics of the catheter 400, 500, 600. For example, each segmentof the outer jacket may have a corresponding Shore D hardness to varythe flexibility along the length of the catheter 400, 500, 600. Theouter jacket segments may be made of a thermoplastic elastomer made offlexible polyether and rigid polyamide (e.g., Pebax®). In someinstances, each segment of the outer jacket may comprise a differentvariation of the thermoplastic elastomer to alter flexiblity.

Catheter 600 may comprise a plurality of discrete segments of the outerjacket with varying flexibility between one or more of the segments. Insome instances, catheter 600 may comprise a plurality of segments. Asidewall property, such as Shore D hardness and/or flexibility, may varybetween the segments. In some instances, a Shore D hardness of the outerjacket segments may gradually transition from higher at proximal endsegment of the outer jacket to lower at a distal end segment of theouter jacket.

The proximal end segment of the outer jacket of the catheter 600 mayhave a Shore D hardness of at least about 60. For example, the Shore Dhardness of the proximal end segment may be from about 70 to about 80or, more specifically, at least about 75.

The distal end segment of the outer jacket of the catheter 600 may havea Shore D hardness of at most about 40. For example, the Shore Dhardness of the distal end segment may be from about 30 to about 20 or,more specifically, no more than about 27.

A plurality of the intermediate segments between the distal end segmentand the proximal end segment may each comprise a variety of Shore Dhardness. In some instances, each segment decreases in a Shore Dhardness in a distal direction and may have a smaller Shore D hardnessthan a proximally adjacent segment. For example, the Shore D hardness ofa first segment may be from about 30 to about 50 or, more specifically,about 40. The first segment, in some instances, may be betweenpositioned about 120 cm to about 160 cm or, more specifically, about 140cm away from a distal end face of the catheter 600. By way of anotherexample, the Shore D hardness of the second segment may be from about 50to about 70 or, more specifically, about 65. The second segment, in someinstances, may be between positioned about 220 cm to about 260 cm or,more specifically, about 240 cm away from a distal end face of thecatheter 600.

Catheter 500 may comprise a plurality of discrete segments of the outerjacket with varying flexibility between one or more of the segments. Insome instances, catheter may comprise a plurality of segments. Asidewall property, such as Shore D hardness and/or flexibility, may varybetween the segments. In some instances, a Shore D hardness of the outerjacket segments may gradually transition from higher at a proximal endsegment of the outer jacket to lower at a distal end segment of theouter jacket.

The proximal end segment of the outer jacket of the catheter 500 mayhave a Shore D hardness of at least about 60. For example, the Shore Dhardness of the proximal end segment may be from about 70 to about 80or, more specifically, at least about 75.

The distal end segment of the outer jacket of the catheter 500 may havea Shore D hardness of at most about 40. For example, the Shore Dhardness of the distal end segment may be from about 30 to about 20 or,more specifically, no more than about 27.

a plurality of the intermediate segments between the distal end segmentand the proximal end segment may each comprise a variety of Shore Dhardness. In some instances, each segment decreases in a Shore Dhardness in a distal direction and may have a smaller Shore D hardnessthan a proximally adjacent segment. For example, the Shore D hardness ofa first segment may be from about 30 to about 50 or, more specifically,about 40. The first segment, in some instances, may be betweenpositioned about 70 cm to about 110 cm or, more specifically, about 90cm away from a distal end face of the catheter 500. By way of anotherexample, the Shore D hardness of a second segment may be from about 50to about 70 or, more specifically, about 65. The second segment, in someinstances, may be between positioned about 160 cm to about 200 cm or,more specifically, about 180 cm away from a distal end face of thecatheter 500.

Catheter 400 may comprise a plurality of discrete segments of the outerjacket with varying flexibility between one or more of the segments. Insome instances, catheter 400 may comprise a plurality of segments. Asidewall property, such as Shore D hardness and/or flexibility, may varybetween the segments. In some instances, a Shore D hardness of the outerjacket segments may gradually transition from a proximal end segment ofthe outer jacket to a distal end segment of the outer jacket.

The proximal end segment of the outer jacket of the catheter 400 mayhave a Shore D hardness of at least about 60. For example, the Shore Dhardness of the proximal end segment may be from about 70 to about 80or, more specifically, about 75.

The distal end segment of the outer jacket of the catheter 400 may havea Shore D hardness of at most about 40. For example, the Shore Dhardness of the distal end segment may be from about 30 to about 20 or,more specifically, no more than about 27.

A plurality of the intermediate segments between the distal end segmentand the proximal end segment may each comprise a variety of Shore Dhardness. In some instances, each segment decreases in a Shore Dhardness in a distal direction and may have a smaller Shore D hardnessthan a proximally adjacent segment. For example, the Shore D hardness ofa first segment may be from about 30 to about 50 or, more specifically,about 40. A first segment, in some instances, may be between positionedabout 65 cm to about 105 cm or, more specifically, about 85 cm away froma distal end face of the catheter 400. By way of another example, theShore D hardness of a second segment may be from about 40 to about 65or, more specifically, about 55. The second segment, in some instances,may be between positioned about 105 cm to about 145 cm or, morespecifically, about 125 cm away from a distal end face of the catheter400. By way of further example, the Shore D hardness of a third segmentmay be from about 60 to about 80 or, more specifically, about 70. Thethird segment, in some instances, may be between positioned about 140 cmto about 180 cm or, more specifically, about 160 cm away from a distalend face of the catheter 400.

Catheter 400 may comprise a tubular body length of about 90+/−5 cm. Insome instances, catheter 400 may comprise a tubular body length of about50+/−5 cm. A number of the plurality of discrete segments of the outerjacket of catheter 400 may vary with respect to the tubular body lengthof catheter 400. A length of the respective segments of the plurality ofdiscrete segments of the outer jacket of catheter 400 may vary withrespect to the tubular body length of catheter 400.

A coating, in some instances, may be located along an outer diameter ofa distal portion of the catheter sidewall. The coating can be configuredto decrease frictional resistance of the distal portion of the cathetersidewall with any adjacent structure (e.g., a vessel wall). In someinstances, the coating increases the lubriciousness of the catheterdistal portion outer sidewall. The coating may advantageously reducefriction on the distal end of the catheter going through tortuousvasculature. This may facilitate advancement and rotation of thecatheter distal end, particularly in situations where the cathetercontains an increased flexibility along a distal end portion of thecatheter. The coating may extend in a proximal direction from, orproximate to, a catheter distal end face. The coating may extend atleast about 20 cm in a proximal direction. In some instances, thecoating extends no farther than about 50 cm from the catheter distal endface. For example, the coating may extend for a length of about 25 cm toabout 35 cm or, more specifically, about 30 cm from a catheter distalend face. It will be understood that the coating may be applied to anycatheter disclosed herein, including, but not limited to, catheters 400,500, 600.

FIG. 8 illustrates a cross section through the sidewall of a distalportion of a single lumen catheter. An internal support layer maycomprise either a coil or braid. In a coil implementation, adjacentloops or filars of the coil 140 may have a constant pitch throughout thelength of the coil or may be closely tightly wound in a proximal zonewith a distal section having looser spacing between adjacent loops. Inan embodiment having a coil section 140 with an axial length of at leastbetween about 20% and about 30% of the overall catheter length, (e.g.,28 cm coil length in a 110 cm catheter shaft 16), at least the distalabout 1 cm or about 2 cm or about 3 cm or about 4 cm of the coil willhave a spacing that is at least about 130%, and in some implementationsat least about 150% or more than the spacing in the proximal coilsection. In a 110 cm catheter shaft 3000 having a Nitinol coil, thespacing in the proximal coil may be about 0.004 inches and in the distalsection may be at least about 0.006 inches or about 0.007 inches ormore.

The distal end of the coil or braid 140 can be spaced proximally fromthe distal end of the inner liner 142, for example, to provide room foran annular radiopaque marker 144. The coil or braid 140 may be set backproximally from the distal end, in some embodiments, by approximately nomore than about 1 cm, about 2 cm, or about 3 cm. In one embodiment, thedistal end of the catheter 12 is provided with a beveled (inclined)distal surface 146 residing on a plane having an angle of at least about10 degrees or about 20 degrees and in one embodiment about 30 degreeswith respect to a longitudinal axis of the catheter 10. At least adistally facing edge of the annular radiopaque marker 144 may be anellipse, residing on a plane which is inclined with respect to thelongitudinal axis to complement the bevel angle of the distal surface146. Additional details are described in connection with FIG. 9 below.

After applying a braid or braid and coil over tie layer 152 and/or overa liner, the distal braid or coil and the RO marker 144 are providedwith an outer jacket 156 such as a polymer tube formed from a pluralityof axially adjacent cylindrical segments to enclose the catheter body16. The outer sleeve 156 may comprise any of a variety of materials,such as polyethylene, polyurethane, polyether block amide (e.g.,PEBAX™), nylon or others known in the art. Sufficient heat is applied tocause the polymer to flow into and embed the proximal braid and distalcoil.

In one implementation, the outer jacket 156 is formed by sequentiallyadvancing a plurality of short tubular segments 133, 132, 130, 128, 126,124, 122, 120 concentrically over the catheter shaft subassembly, andapplying heat to shrink the sections on to the catheter 12 and provide asmooth continuous outer tubular body. The foregoing segmentedconstruction may extend along at least the most distal about 10 cm, andpreferably at least about the most distal about 20 cm, about 25 cm,about 30 cm, about 35 cm, about 40 cm, or more than about 40 cm of thecatheter body 10. The entire length of the outer jacket 156 may beformed from tubular segments and the length of the distal tubularsegments may be shorter than the one or more tubular segments formingthe proximal portion of the outer jacket 156 proximal to the junctionbetween the braid 150 and coil 140 in order to provide proximal backupsupport and steeper transitions in flexibility toward the distal end ofthe catheter 12.

The durometer of the outer wall segments may decrease in a distaldirection. For example, proximal segments such as 133 and 132, may havea durometer of at least about 60 D or about 70 D, with gradual decreasein durometer of successive segments in a distal direction to a durometerof no more than about 35 D or about 25 D or lower. A 25 cm section mayhave at least about 3 or about 5 or about 7 or more segments and thecatheter 12 overall may have at least about 6 or about 8 or about 10 ormore distinct flexibility zones. The distal 1 or 2 or 4 or more segments122, 120, may have a smaller OD following shrinking than the moreproximal segments 133-124 to produce a step down in OD for the finishedcatheter body 16. The length of a lower OD section 160 may be within therange of from about 3 cm to about 15 cm and, in some embodiments, iswithin the range of from about 5 cm to about 10 cm such as about 7 cm orabout 8 cm and may be accomplished by providing the distal segments 122,120 with a lower wall thickness.

In another embodiment, the most distal portion of the catheter 12 maycomprise a durometer of less than approximately 35 D (e.g., 25 D) toform a highly flexible distal portion of the catheter and have a lengthbetween approximately 25 cm and approximately 35 cm. The distal portionmay comprise one or more tubular segments of the same durometer (e.g.,segment 120). A series of proximally adjacent tubular segments may forma transition region between a proximal stiffer portion of the catheter12 and the distal highly flexible portion of the catheter. The series oftubular segments forming the transition region may have the same orsubstantially similar lengths, such as approximately 1 cm.

The relatively short length of each of the series of tubular segmentsmay provide a steep drop in durometer over the transition region. Forexample, the transition region may have a proximal tubular segment 122(proximally adjacent the distal portion) having a durometer ofapproximately 35 D. An adjacent proximal segment 124 may have adurometer of approximately 55 D. An adjacent proximal segment 126 mayhave a durometer of approximately 63 D. An adjacent proximal segment 128may have a durometer of approximately 72 D.

More proximal segments may comprise a durometer or durometers greaterthan approximately 72 D and may extend to the proximal end of thecatheter. For instance, a catheter segment may comprise a proximalportion greater than approximately 72 D between about 1 cm and about 3cm. In some embodiments, the proximal portion may be about 2 cm long. Insome embodiments, the most distal segments (e.g., 120, 122) may comprisePEBAX™ and more proximal segments may comprise a generally stiffermaterial, such as Vestamid®.

The inner diameter of the catheter 10 may be between approximately 0.06and 0.08 inches, between approximately 0.065 and 0.075 inches, orbetween approximately 0.068 and 0.073 inches. In some embodiments, theinner diameter is approximately 0.071 inches.

In some embodiments, the distal most portion may step or taper to adecreased inner diameter such as under segments 122 and 120. The tapermay occur approximately between the distal highly flexible portion andthe transition region (e.g., over the most proximal portion of thedistal highly flexible portion). The taper may be relatively gradual(e.g., occurring over approximately 10 or more cm) or may be relativelysteep (e.g., occurring over less than approximately 5 cm). The innerdiameter may taper to an inner diameter between about 0.03 and about0.06 inches. For example, the inner diameter may be about 0.035 inches,about 0.045 inches, or about 0.055 inches at the distal end of thecatheter 12. In some embodiments, the inner diameter may remainconstant, at least over the catheter extension segment.

In some hybrid coil/braid embodiments, the coil 140 may extendproximally from a distal end of the catheter 12 along the highlyflexible distal portion ending at or overlapping with the distal end ofthe braid 150. In other embodiments, the coil 140 may extend the entirelength of the catheter 12. The braid 150, when present, may extend fromabout the transition 163 the proximal end of the coil 140 to theproximal end of the catheter 12.

Any of the catheters disclosed herein may be provided with an angleddistal tip. Referring to FIG. 9 , distal catheter tip 18 comprises atubular body 14 which includes an advance segment 200, and a marker band144. An inner tubular liner 142 may extend throughout the length of thedistal catheter tip and may comprise dip coated PTFE.

A reinforcing element 140 such as a braid and/or spring coil is embeddedin an outer jacket which may extend the entire length of the catheterproximally of the radiopaque marker.

The advance segment 200 terminates distally in an angled face 146, toprovide a leading side wall portion 202 having a length measured betweenthe distal end 204 of the marker band 144 and a distal tip 206. Atrailing side wall portion 208 of the advance segment 200, has an axiallength in the illustrated embodiment of approximately equal to the axiallength of the leading side wall portion 202 as measured at approximately180 degrees around the catheter from the leading side wall portion 202.The leading side wall portion 202 may have an axial length within therange of from about 0.1 mm to about 5 mm and generally within the rangeof from about 1 to 3 mm. The trailing side wall portion 208 may be atleast about 0.1 or 0.5 or 1 mm or 2 mm or more shorter than the axiallength of the leading side wall portion 202, depending upon the desiredperformance.

The angled face 146 inclines at an angle A within the range of fromabout 45 degrees to about 80 degrees from the longitudinal axis of thecatheter. For certain implementations, the angle is within the range offrom about 50 degrees to about 70 degrees or within the range of fromabout 55 degrees to about 65 degrees from the longitudinal axis of thecatheter. In one implementation, the angle A is about 60 degrees. Oneconsequence of an angle A of less than 90 degrees is an elongation of amajor axis of the area of the distal port which increases the surfacearea of the port and may enhance clot aspiration or clot retention.Compared to the surface area of the circular, transverse port (angle Ais 90 degrees), the area of the angled port is generally at least about105%, and no more than about 130%, in some implementations within therange of from about 110% and about 125% and in one example is about115%.

In the illustrated embodiment, the axial length of the advance segmentis substantially constant around the circumference of the catheter, sothat the angled face 146 is approximately parallel to the distal surface210 of the marker band 144. The marker band 144 has a proximal surfaceapproximately transverse to the longitudinal axis of the catheter,producing a marker band 144 having a right trapezoid configuration in aside elevational view. A short sidewall 212 is rotationally aligned withthe trailing side wall portion 208, and has an axial length within therange of from about 0.2 mm to about 4 mm, and typically from about 0.5mm to about 2 mm. An opposing long sidewall 214 is rotationally alignedwith the leading side wall portion 202. Long sidewall 214 of the markerband 144 is generally at least about 10% or 20% longer than shortsidewall 212 and may be at least about 50% or 70% or 90% or more longerthan short sidewall 212, depending upon desired performance. Generally,the long sidewall 214 will have a length of at least about 0.5 mm or 1mm and less than about 5 mm or about 4 mm.

Any of the marker bands described herein may be a continuous annularstructure, or may optionally have at least one and optionally two orthree or more axially extending slits throughout its length. The slitmay be located on the short sidewall 212 or the long sidewall 214 or inbetween, depending upon desired bending characteristics. Any of themarker bands described herein may comprise any of a variety ofradiopaque materials, such as a platinum/iridium alloy, with a wallthickness preferably no more than about 0.003 inches and in oneimplementation is about 0.001 inches.

The advance segment 200 may comprise a distal extension of the outerpolymer jacket and optionally the inner liner, without other internalsupporting structures distally of the marker band 144. The outer jacketmay comprise extruded Tecothane and/or PEBAX. The advance segment 200may have a bending stiffness and radial crush stiffness that is no morethan about 50%, and in some implementations no more than about 25% or15% or 5% or less than the corresponding value for the adjacent proximalcatheter body.

The proximal end of the catheter 12 is preferably provided with ahemostasis valve, to facilitate introduction of a thrombus engagementtool or a secondary catheter there through. The hemostasis valve may becarried by the connector module 30, or directly by the proximal catheterconnector 22. Any of a variety of hemostasis valve configurations may beused.

Referring to FIGS. 10A-10C, there is illustrated a valve inserter inaccordance with another embodiment. The inserter enables opening a valve(e.g., the hemostasis valve and/or an introducer sheath valve having anelastomeric membrane valve with a passive slit) and supporting it in anopen configuration while providing an access lumen therethrough toenable a delicate secondary device such as a thrombus engagement tool ora catheter to advance therethrough without encountering any resistanceor damage from the valve.

The inserter 300 comprises an elongate tubular body 302 having aproximal end 304, a distal end 306, and a central lumen 308 extendingtherethrough. The tubular body 302 has an inside diameter sufficient toaccommodate the secondary device, and an OD capable of passing through acompatible hemostasis valve. In general, tubular body will have anoutside diameter within the range of from about 0.04″ to about 0.1, anda length within the range of from about 1″ to about 4″. Tubular body 302can be formed as an extrusion from any of a variety of common catheterpolymers such as Nylon, PEEK, polyethylene, polyimide or others known inthe art having sufficient crush resistance and column strength to enterand to maintain patency under the closing pressure of a hemostasisvalve.

The proximal end 304 of the tubular body 302 may be provided with afunnel shaped landing zone 322 leading to the central lumen, tofacilitate introducing the distal tip of the secondary device into theinserter. In the illustrated embodiment, the proximal end of the tubularbody is provided with an inclined face 314. A distal, leading edge 316of the inclined face 314 is axially distally spaced apart from thetrailing proximal edge 318 of the face 314 by a distance D. The distanceD [between 316 and 318] may be at least about 0.1″ and typically no morethan about 0.5″.

The inclined face cooperates with the curved sidewall of the tube tocreate a side opening for funneling the distal tip of the secondarydevice into the proximal end of the lumen. For this purpose, the sidewall at the trailing edge 318 may be provided with a curvature having agreater radius than the radius of curvature at the leading edge 316 witha progressively changing radius in between, creating a funnel shape forthe landing zone 322.

The tubular body 302 is provided with an axially extending slit 310extending between the distal end 306 and the leading edge 316 of theinclined face 314, to enable the inserter to be peeled away laterallyfrom the secondary device extending therethrough once the inserter hasenabled passage of the secondary device through the hemostasis valve.

A pull tab 312 may be provided on the proximal end of the tubular body302 to enable the inserter 300 to be grasped and pulled away from thesecondary device extending therethrough. The pull tab 312 may beintegrally formed with the tubular body 302 (e.g., as a portion of thesidewall of the tube stock as illustrated) or attached thereto such asby adhesive bonding or mechanical compression or interferenceengagement. In the illustrated embodiment, the pull tab 312 inclineslaterally away from the longitudinal axis of the tubular body, to allowcoaxial approach and introduction of the catheter into the inserter 300.

In one implementation of the inserter, the tubular body has asubstantially constant diameter throughout most (e.g., at least about80% or 90%) of its length overall. However, at least the outsidediameter in a distal nose segment 324 may be necked down to a smalleroutside diameter at the distal end. This enables the inserter to betterenter the hemostasis valve under distal compression. In one example, thetubular body has an 8 French ID along most of its length but necks downto 6 French in the distal nose segment 324. This inserter willfacilitate the introduction of either a 6 French or an 8 French catheterthrough the hemostasis valve, since the 8 French catheter can simplyforcibly dilate the necked distal end due to the axial slit 310.

In one implementation, the concave entrance funnel surface of thelanding zone 322 may be provided with a visual indicium such as adifferent color than the outside surface of the tubular body 302, tofacilitate visualization of the funnel opening and assist in loading thesecondary catheter into the funnel. This may be accomplished byproviding a colored coating on either the inside or outside surface ofthe tube stock, or by forming at least a portion of the tube stock as acoextrusion of dissimilar colored materials.

Example Embodiments

A clot capture module for use in a thrombectomy system, the clot capturemodule comprising one or more of the following:

a housing;

a clot capture chamber in the housing;

a window in the housing to permit visual inspection of the clot capturechamber;

a filter in the clot capture chamber, the filter being visible throughthe window, the filter having an upstream surface and a downstreamsurface;

an incoming flow path configured to direct incoming blood from anaspiration catheter against the upstream surface of the filter;

a normally closed aspiration control valve in the incoming flow path,the aspiration control valve configured to block flow of incomingaspirated blood until actuated to permit inflow of aspirated blood; and

an outgoing flow path configured to direct blood from a downstream sideof the filter to a remote vacuum canister.

A clot capture module as described in any embodiment herein, furthercomprising a normally closed vent being openable to permit air to bedrawn into the clot capture chamber.

A clot capture module as described in any embodiment herein, wherein theupstream surface of the filter is visible through the window.

A clot capture module as described in any embodiment herein, wherein theupstream surface of the filter is substantially planar.

A clot capture module as described in any embodiment herein, wherein theupstream surface of the filter is convex.

A clot capture module as described in any embodiment herein, wherein thefilter comprises a blood permeable membrane, and wherein the upstreamsurface of the filter is on a radially outwardly facing surface of theblood permeable membrane.

A clot capture module as described in any embodiment herein, wherein theblood permeable membrane at least partially encloses a filtered bloodchamber which is in fluid communication with the outgoing flow path.

A clot capture module as described in any embodiment herein, wherein thewindow comprises a transparent tubular portion of the housing.

A clot capture module as described in any embodiment herein, furthercomprising an aspiration actuator, configured to control the aspirationcontrol valve.

A clot capture module as described in any embodiment herein, wherein theaspiration actuator comprises a rocker switch.

A clot capture module as described in any embodiment herein incombination with a vacuum line leading to an aspiration pump andcanister, wherein the clot capture module is configured to reside withina sterile field while the aspiration pump and canister reside outside ofthe sterile field.

A clot capture module as described in any embodiment herein, wherein thevacuum line is at least about 30 inches in length.

A clot capture module as described in any embodiment herein, wherein theaspiration control valve comprises collapsible tubing.

A clot capture module as described in any embodiment herein, furthercomprising a selector valve in the vacuum line.

A clot capture module as described in any embodiment herein, wherein theaspiration pump comprises a syringe.

A clot capture module as described in any embodiment herein, comprisinga proximal housing, and a distal housing separated by a transparenttubular side wall.

A clot capture module as described in any embodiment herein, wherein atleast one of the proximal housing and distal housing is releasablyconnected to the transparent tubular side wall.

A clot capture module as described in any embodiment herein, furthercomprising a coating to inhibit blood accumulation on an interiorsurface of the window.

A thrombus engagement tool configured to be advanced through a catheterand to engage thrombus, the thrombus engagement tool comprising one ormore of the following:

a rotatable core having a proximal end and a distal end; and

a thrombus engagement tip on the distal end of the rotatable core, thethrombus engagement tip comprising:

a helical thread;

an advance segment on a distal side of the helical thread; and

a trailing segment on a proximal side of the helical thread.

A thrombus engagement tool as described in any embodiment herein,further comprising a projection carried by the rotatable core, theprojection being underneath at least one of the advance segment and thetrailing segment to form an interference fit with the thrombusengagement tip.

A thrombus engagement tool as described in any embodiment herein,wherein the projection comprises an annular ring.

A thrombus engagement tool as described in any embodiment herein,wherein the projection comprises a radiopaque marker.

A thrombus engagement tool as described in any embodiment herein,comprising a first radiopaque marker under the advance segment and asecond radiopaque marker under the trailing segment.

A thrombus engagement tool as described in any embodiment herein,wherein an outer periphery of the helical thread substantially conformsto a surface of a cylinder.

A thrombus engagement tool as described in any embodiment herein,wherein the helical thread comprises a proximal surface which inclinesradially outwardly in a proximal direction to define a proximallyopening undercut.

A thrombus engagement tool as described in any embodiment herein,further comprising a handle on the proximal end of the rotatable core.

A thrombus engagement tool as described in any embodiment herein,comprising a limit bearing surface on the handle, the limit bearingsurface being configured to limit projection of the thrombus engagementtip in a distal direction relative to a distal end of the aspirationcatheter.

A thrombus engagement tool as described in any embodiment herein,wherein the advance segment, the helical thread, and the trailingsegment are all molded onto the rotatable core.

A thrombus engagement tool as described in any embodiment herein,wherein the rotatable core is cannulated.

A thrombus engagement tool as described in any embodiment herein,wherein the rotatable core is a solid wire.

A thrombus engagement tool as described in any embodiment herein,wherein the advance segment comprises an atraumatic tip.

A thrombus engagement tool as described in any embodiment herein,wherein the atraumatic tip comprises a soft polymer.

A thrombus engagement tool as described in any embodiment herein,wherein the handle further comprises an indicium of rotationaldirection.

A thrombus engagement tool as described in any embodiment herein,wherein the thrombus engagement tip has an axial length within the rangeof from about 15 mm to about 30 mm.

A thrombus engagement tool as described in any embodiment herein incombination with a catheter having an inside diameter, wherein anoutside diameter of the helical thread is no more than about 60% of theinside diameter of the catheter.

A thrombus engagement tool as described in any embodiment herein,wherein the outside diameter of the helical thread is no more than about40% of the inside diameter of the catheter.

A thrombus engagement tool as described in any embodiment herein,further comprising a position indicator carried by the rotatable core.

A thrombus engagement tool as described in any embodiment herein,wherein the position indicator comprises a distal end of a tubesurrounding the rotatable core.

A method of removing embolic material from a vessel with mechanical andaspiration assistance, the method comprising one or more of thefollowing:

providing an aspiration catheter having a central lumen and a distalend;

advancing the distal end to obstructive material in a vessel;

applying vacuum to the central lumen to draw clot into the centrallumen;

introducing a thrombus engagement tool into the central lumen, thethrombus engagement tool having a tip comprising a helical thread havinga major diameter that is at least about 0.015 inches smaller than aninside diameter of the central lumen, the helical thread beingconfigured to provide an aspiration flow path around the tip; and

manually manipulating the tip to engage clot between the tip and aninside wall of the central lumen.

A method of removing embolic material as described in any embodimentherein, wherein the tip is carried by a rotatable core having a proximalhandle.

A method of removing embolic material as described in any embodimentherein, wherein the rotatable core is cannulated.

A method of removing embolic material as described in any embodimentherein, wherein the rotatable core is a microcatheter.

A method of removing embolic material as described in any embodimentherein, wherein the rotatable core is a wire.

A method of removing embolic material as described in any embodimentherein, wherein the axial length of the threaded portion of the tip iswithin the range of from about 5 mm to about 15 mm.

A method of removing embolic material as described in any embodimentherein, further comprising the step of introducing the catheter via afemoral artery prior to the advancing step.

A method of removing embolic material as described in any embodimentherein, comprising the step of advancing the catheter to a pulmonaryembolism.

A method of removing embolic material as described in any embodimentherein, comprising the step of advancing the catheter to a deep venousthrombosis.

A method of removing embolic material as described in any embodimentherein, comprising the step of introducing a thrombus engagement toolhaving a tip with a major diameter that is no more than about 60% of theinside diameter of the central lumen.

A method of removing embolic material as described in any embodimentherein, comprising introducing a thrombus engagement tool having a tipwith a major diameter that is no more than about 40% of the insidediameter of the central lumen.

A method of removing embolic material as described in any embodimentherein, wherein the tip is laterally displaced within the central lumenin response to the ingestion of clot.

A method of removing embolic material as described in any embodimentherein, wherein an outer profile of the threaded tip in an end view issubstantially circular.

A method of removing embolic material as described in any embodimentherein, wherein the thread has a proximal face and a distal face, andthe proximal face inclines radially outwardly in a proximal direction.

A method of removing embolic material as described in any embodimentherein further comprising axially reciprocating the thrombus engagementtool within the catheter.

A method of removing embolic material as described in any embodimentherein, further comprising axially extending the tip beyond the distalend of the catheter.

A method of removing embolic material as described in any embodimentherein, comprising extending the distal tip at least about 2 cm beyondthe distal end of the catheter.

A method of removing embolic material as described in any embodimentherein, comprising axially aligning the distal tip with the distal endof the catheter using a position indicator on the rotatable core.

A method of removing embolic material as described in any embodimentherein, further comprising advancing the thrombus engagement toolthrough a rotating hemostasis valve before introducing the thrombusengagement tool into the central lumen.

A method of removing embolic material as described in any embodimentherein, wherein the position indicator provides haptic feedback as theposition indicator passes through the hemostasis valve.

An inserter for guiding a device through a valve, the insertercomprising one or more of the following:

an elongate tubular body having a proximal end, a distal end, and asidewall at least partially defining a central lumen;

a laterally facing concave landing zone on the proximal end, the concavelanding zone having a radius of curvature that increases in a proximaldirection; and

an axially extending slit in the sidewall, the axially extending slitextending from the distal end to the concave landing zone.

An inserter as described in any embodiment herein, further comprising atapered distal tip.

An inserter as described in any embodiment herein, further comprising apull tab.

An inserter as described in any embodiment herein, wherein a surface ofthe concave landing zone comprises a different color than an outsidesurface of the elongate tubular body.

A method of passing a device through a valve, the method comprising oneor more of the following:

providing an inserter having a tubular body with a split sidewall;

advancing the tubular body through a valve;

advancing a device through the tubular body and beyond the valve; and

proximally retracting the tubular body so that the device escapeslaterally from the tubular body through the split sidewall, leaving thedevice in place across the valve.

A method of passing a device through a valve as described in anyembodiment herein, wherein advancing the tubular body through the valvecomprises advancing a tapered distal tip on the tubular body through thevalve.

A method of passing a device through a valve as described in anyembodiment herein, wherein advancing the tubular body through the valveis accomplished with the device pre loaded inside the tubular body.

A method of passing a device through a valve as described in anyembodiment herein, wherein a distal nose segment of the tubular bodyexpands in diameter in response to advancing the device therethrough.

A method of passing a device through a valve as described in anyembodiment herein, wherein the device is a thrombus engagement tool.

A method of passing a device through a valve as described in anyembodiment herein, wherein the device is a secondary catheter.

A method of passing a device through a valve as described in anyembodiment herein, wherein the device is an aspiration catheter.

1. A clot capture module for use in a thrombectomy system, the clotcapture module comprising: a housing; a clot capture chamber in thehousing; a window in the housing to permit visual inspection of the clotcapture chamber; a filter in the clot capture chamber, the filter beingvisible through the window, the filter having an upstream surface and adownstream surface; an incoming flow path configured to direct incomingblood from an aspiration catheter against the upstream surface of thefilter; a normally closed aspiration control valve in the incoming flowpath, the aspiration control valve configured to block flow of incomingaspirated blood until actuated to permit inflow of aspirated blood, theaspiration control valve comprising collapsible tubing; and an outgoingflow path configured to direct blood from a downstream side of thefilter to a remote vacuum canister.
 2. (canceled)
 3. A clot capturemodule as in claim 1, wherein the upstream surface of the filter isvisible through the window.
 4. A clot capture module as in claim 1,wherein the upstream surface of the filter is substantially planar.
 5. Aclot capture module as in claim 1, wherein the upstream surface of thefilter is convex.
 6. (canceled)
 7. (canceled)
 8. A clot capture moduleas in claim 1, wherein the window comprises a transparent tubularportion of the housing.
 9. A clot capture module as in claim 1, furthercomprising an aspiration actuator, configured to control the aspirationcontrol valve.
 10. A clot capture module as in claim 9, wherein theaspiration actuator comprises a rocker switch.
 11. (canceled) 12.(canceled)
 13. (canceled)
 14. (canceled)
 15. (canceled)
 16. A clotcapture module as in claim 1, comprising a proximal housing, and adistal housing separated by a transparent tubular side wall.
 17. A clotcapture module as in claim 16, wherein at least one of the proximalhousing and distal housing is releasably connected to the transparenttubular side wall.
 18. A clot capture module as in claim 1, furthercomprising a coating to inhibit blood accumulation on an interiorsurface of the window.